Alright, so this is roughly the problem (and pardon me for not being very clear, since my monitor won't turn on, I can't remember exactly what it said):

The computer is supposedly not very old (but who can you believe, right?), it's a Pentium IV processor with a newer monitor. It actually belongs to my grandfather and I don't work on it. Lately it started spontaneously freezing up and the restart button and/or ctl+alt+del didn't work. We had to press on the powerbar button that it's connected to to restart it.

Then, today, it started up normally but then started running in circles. It starts up, checks memory, then restarts again. The message that it displayed was something like 'CPU is not readable (or configured??), please check CPU Soft Menu' (which is in setup).

So, I checked the CPU Soft menu and since I have no idea what it all means, I tried changing the settings but as soon as I pressed 'Save&Exit', it restarted again and when I went back to the menu, it had the old values for the CPU. Then, out of the blue, it stopped turning on the monitor. The processor would make a normal sound but the monitor wouldn't light up (though it's plugged in and it's working).

At this point, I guess the only way to do it is do something physical with the processor, right? But what? I'm not going to mess with it myself. I'm computer literate but I'm not a technician. I only cleaned the fan and inside of the processor very gently but it didn't do anything.

Any advice?

it sounds as though you might have a cpu thats gone faulty. if this is the case you will need to get a new one and possibly a new motherboard too

Ah, I was afraid it was the CPU after all. Oh well, thanks for confirming. I guess I'll.. seek help now. :-|

See if you can borrow a cpu for testing before you spend the cash. If you still get the error, then you know it just might be only the motherboard.

I've also seen ppl install cpu's rotated the wrong way. And yes, the pins only line up one way, which made it all the more amusing and unbelievable.

Well, it should be installed the right way cause it did work for about half a year but the processor itself I think is pretty old and since we got it from a secondary source, I don't even know if it can be trusted. You can put anything in a pretty box but the insides might be ancient, you know?

So thanks again for all the advice!

know exactly what u mean.. out of curiosity how old is the processor. I.E is it one of the first P4 processors that shipped with PCs about 4/5 years ago when Win xp was first released.

secondly dont trust secondhand goods